The invention relates to a circular knitting machine.
The carding devices of all circular knitting machines of this kind used for industrial purposes contain at least one separating cylinder or card cylinder to which a fiber strand is fed, and a transfer cylinder for receiving and transferring the fibers prepared by the separating cylinder to the hooks of the knitting needles. The separating and transfer cylinders are provided with flexible wire hooks projecting outwardly and meshing with one another, and the transfer of the fibers from the transfer cylinders to the hooks of the knitting needles is accomplished by running the latter through the wire hooks of the transfer cylinder (U.S. Pat. Nos. 3,896,636 and 3,896,637 and British Pat. No. 177,472). The mechanical meshing of the wire hooks of the transfer cylinder with the wire hooks of the separating cylinder results in great mechanical wear and an undesirable interdependence between the rotatory speed of the separating cylinders and transfer cylinders.
Therefore circular knitting machines have become known which have devices for the contactless transfer of the fibers to the needle hooks, the term "contactless" meaning that the needle hooks do not pass through any kind of card clothing, and preferably also no cylinders have to be provided having intermeshing card clothing. Such knitting machines have a means for pulling the fiber strand apart, which is followed by a transport channel carrying the singled fibers in a stream, whereby the fibers are laid into needle hooks moving across the fiber stream. All other known circular knitting machines with contactless fiber transfer are made in a similar manner (German Pat. Nos. 97,374 and 1,585,081, German Auslegeschrift No. 1,785,465 and German Offenlegungsschrift Nos. 2,253,659, and 2,430,867 and U.S. Pat. No. 3,996,770), but they have not been put to practical use because the transfer of the fibers to the needle hooks is unreliable.
Experiments on a similar circular knitting machine in accordance with an as yet unpublished proposal of the same applicant (Patent Application P 3,107,714), which has a carding cylinder driven at high circumferential velocity and distinguishes itself from the known machines by an extremely short transport passage free of directional changes for the fiber stream, and therefore a very uniform fiber transfer, have shown that the fibers often are bound into the loops of the knit goods, not just by one needle but by several adjacent needles. This results in a strengthening of the knit goods in the direction of the rows of stitches, which in some cases may be desirable, but in many applications is not. Probably this phenomenon is caused by the fact that the fiber stream transporting the fibers from the carding device to the needle hooks contains a marked percentage of fibers lying across the fiber stream, which upon encountering the needle hooks are laid simultaneously into several needle hooks.
The invention is therefore addressed to the problem of creating, on a circular knitting machine with contactless fiber transfer of the kind specified in the beginning, by means of which the percentage of the fibers bound across several loops by several needles can be influenced and thus either considerably reduced or varied between two limit values.